Log is the abbreviation for logarithm.
The logarithm is an operator that is used to find at which power you have to raise a number to get another.
In other words,
\(\forall n\in \mathbb{R}_{+}^{*},\forall b\in \mathbb{R}_{+}^{*}, \\\text{If } \log_b(n)=p\text{, then }b^p=n.\)
(The number b is called the base of the logarithm.)
Examples:
- log2(16)=4 because 24=16
- log10(100)=2 because 102=100
- loge(e8) is 8*.
*The number e is an irrationnal number called Euler's number (e≈2.71828182845904523536028747135266249775724709369995...). The logarithm of a number n to base e is also called natural logarithm of n and written ln(n).